Incubator temperature control question

If I have read the signs correctly and all goes well, I should have my first clutch of eggs in about a month. I’m building an incubator and need some advice on heat and temperature monitoring. I plan on using THG heat tape and a Vivarium VE-300X2 temperature controller. The inside dimensions are 18” deep 22” wide and 48” tall. I will have wire shelves and a fan(s) circulating the air to keep the temperature the same throughout the enclosure. I plan on placing the temperature probe from the VE-300X2 near the back and top of the unit with the temperature set at 89’F.
I’ve heard of people placing probes in the egg box and even placing them in the middle of the pile of eggs (in the egg box). Is this necessary or will the temperature probe placed inside the incubator as I described, be sufficient?
Thanks for your help - Andy

I personally put the probe in the egg box. Theoretically you should have an even temperature throughout, especially if you have good insulation and something in there to help retain/stabilize heat (eg water bottles, bricks). But I want to know what the temp is inside the box where the eggs are and have temps adjust to that, not what the temps are outside the box.

And I'd put it towards the middle of the rack so you get a more "average" temperature. If its near the top, then that might cause the bottom to be a little cooler, and vice versa. Though with fans, shouldn't be an issue, but I'd still put it towards the middle. I also do that on my racks that way.

i researched thermal capacity last time it came up, and per unit of volume water bottles have the highest thermal capacity. higher than water with salt or otherwise impure water, higher than stone or ceramics, even higher than blocks of solid metal. by volume, water beats a block of copper even while the copper is around 7-8 times heavier by volume. so as stabilizers, sealed PET water bottles are totally the way to go.

if the individual egg boxes are completely sealed, i see no reason to place the temp probe inside an egg box, since there should be perfect or near-perfect thermodynamic equilibrium. (can be confirmed with temp gun). if the egg boxes are not completely sealed, there may be evaporation cooling going on, so a probe inside an egg box makes sense. again, a temp gun and test runs will clarify things.

That thermostat is proportional so you'll be good using that. I love my 300x2!

As far as the probe. I put my probe in an extra egg tub, with perl and water. Sometimes I put it in an egg tub with eggs (if I don't have any extra egg tubs ready). I have also put the probe in the middle of the incubator for an entire season. In my experience it doesn't matter what you do, it will all work out as long as you don't have any spikes.